How's this for a great tip: Check out "Jar of Hearts," the debut single by 23-year-old L.A. waitress Christina Perrihere. Sound familiar already? But of course: the magnetic ballad is now a No. 10 iTunes hit after it found its way into So You Think You Can Dance choreographer Stacey Tookey's duffel bag and ended up on the June 30th episode. The next day, the ditty was on the Top 15 iTunes singles chart and it as since well over 100,000 copies!

And to think, just three weeks ago Perri was hoisting hash at L.A.'s Melrose Place Café and, on July 15, she performed the track live on the hit reality show. UsMagazine.com decided to catch up with her before she got too big to take my calls last week. Read on for the lowdown.

UsMagazine.com: This has been a whirlwind for you! How are you feeling?

Christina Perri: I am feeling beyond ecstatic. It really hasn't stopped-this otherworldly feeling. It doesn't seem real, but at the same time I know it is. I just can't stop smiling!

Us: You were working as a waitress just two weeks ago, and now "Jar of Hearts" has sold 100,000 copies!

CP: Yeah! I worked at a café from January until two weeks ago. It's a café in Beverly Hills and, you know, it was just my day job. It was how I survived and was able to live in L.A. and do these things. I would work at the café from 9-5, and then I'd be in the studio from 5-11. I was working insane days that all kind of rolled into each other, but the more important thing was that I was working on my music. I just did the café job like we all do to survive. It was a really kind of cool moment where I realized I could just focus on my music now.

Us: I know that waiters and waitresses encounter a lot of interesting people. Any crazy stories?

CP: Oh my God. The café is on Melrose Place, and let me just say, without revealing anything, they don't need a scripted television show called Melrose Place. They could totally have a reality show about the people on the block, including myself! There was so much drama and everybody would come to my café and just spill it during my lunch break to me. I would be like 'Please stop telling me this. I know way too much about all of you!' [laughs] It was really awesome.

Us: And being that you were in Beverly Hills, did you ever wait on any celebrities?

CP: Well, I waited on Ted Danson, some of the people from Twilight, Anna Paquin and Amy Adams. Brett Ratner came in a bunch, and he loves me. I made him the best iced coffee drink he says he's ever had. The Twilight people I couldn't even breathe around because I'm such a big Twi-hard. I waited on Rachelle Lefevre and then Esme, the mom, Elizabeth Reaser. I saw Michael Cera the other day too. He's really hot in person! He's like geeky hot, I couldn't get over it. [laughs]

Us: You must have been thrilled to tell your bosses at the café that you were peacing out after your music career took off overnight.

CP: I always dreamed I would have this big dramatic exit where I'd hop into my limo and take off and be like, 'See ya later!' But it wasn't like that at all. The people I worked with were like family by the time I left. But I was like ‘Hey, so, I got this thing, and I’m going to cover one shift at a time until somebody can take over full time.' It was not dramatic at all. My coworkers are so incredibly proud of me.

Us: And then your song is featured on So You Think You Can Dance! What was it like to get the call that choreographer Stacey Tookey was going to use it in a routine?

CP: That was definitely the big moment. For a little while, we didn't know if it was going to happen. Stacey heard the song, and we knew that she liked it, but there was that 'Hey, I've got to pitch it to my producers' kind of thing so don't get your hopes up. And that was how we were for a good eight days or so, and then a couple days before the show, I got the call that it was definitely happening that Wednesday and it was just madness from that moment on.

Us: Were you in the audience that night or did you throw a little party at home?

CP: I was in the audience! It was so cool. I was sitting there. I brought my friend Keltie Colleen who was the one who sent it to Stacey Tookey. She's my best friend on the planet, so I brought her as my date, naturally. She was sitting next to me, bawling her eyes out the whole time. I got to see them dance to it live, and the feeling was really indescribable, especially the girl Kathryn who did the dance. She contacted me two days before to ask about [my motivations] for writing the song, and when she danced to it, I couldn't help but feel like I was onstage dancing. Five minutes after the dance happened, I looked down at my phone and it just started blowing up.

CP: That's been the overwhelming response! What's been really cool is that everybody has been writing me and telling me their stories. I love it!

Us: The song is obviously about something deeply personal you were experiencing. When did you write it?

CP: I wrote it in December. It was just one of the songs I had on my EP. That's what happened. I started working with Silva Management in February, and they put me in the studio, and I was just recording my EP at a normal pace. This was just one of the songs on my EP, and it just so happened that my friend Keltie, who sent it to Stacey, thought 'This could be really rad for the show.' Then it all happened.

Us: Can I ask what the back-story is?

CP: I was literally in Philadelphia, which is where I'm from, in December in my childhood bedroom, literally hiding from this boy who broke my heart but wanted to see me. I wrote this song legitimately going through it.

Us: Is that representative of the sound that we can expect to hear on the rest of your album?

CP: "Jar of Hearts" was actually very unique in the sense that it doesn't have full instrumentation. It's very just basic and pretty with the strings and piano. The EP I'm making and the songs that will follow up are definitely a better representation of me, which is drums and guitars. The record is a good mix between indie and old school pop. My managers describe my music as if The Beatles and Jason Mraz and Amy Winehouse and Fiona Apple had a love child, it would be me.

Us: So lastly, here's my burning question...how the hell are you still unsigned?

CP: Well, I don't think I’m going to be unsigned for long. I’ll just say that!

For more on Christina Perri and her debut disc on the way, check out her Web site.